The invention concerns a shoe press for a paper or board machine, the shoe press having a press shoe which together with a counter roll forms an extended nip for a paper or cardboard web and for a flexible circulated belt. In such shoe presses, it is known to provide at least one piston-and-cylinder assembly arranged between a supporting beam associated with the frame system of the shoe press and the press shoe and in which hydraulic fluid is supplied to a working chamber. In some types of shoe presses, the working chamber of the piston-and-cylinder assembly communicates with a compartment via a throttle, the compartment being arranged on the outside of the piston-and-cylinder assembly in such a manner that the hydraulic fluid therein directly or indirectly exerts a force upon the press shoe in the direction opposite to that of the force exerted upon the press shoe by the hydraulic fluid in the working chamber.
A shoe press as described above is disclosed in DE 195 15 832 C1. The compartment is defined in a face of the piston of the piston-and-cylinder assembly.
This shoe press suffers from the drawback that lateral forces which in operation affect the press shoe are transmitted to the cylinder jacket and the piston, which may cause a jam between the press shoe and the piston.